Benefit of antiretroviral therapy on survival of human immunodeficiency virus-infected patients admitted to an intensive care unit

Abstract

Objective: To evaluate the impact of antiretroviral therapy (ART) and the prognostic factors for in-intensive care unit (ICU) and 6-month mortality in human immunodeficiency virus (HIV)-infected patients.

Design: A retrospective cohort study was conducted in patients admitted to the ICU from 1996 through 2006. The follow-up period extended for 6 months after ICU admission.

Setting: The ICU of a tertiary-care teaching hospital at the Universidade de São Paulo, Brazil.

Participants: A total of 278 HIV-infected patients admitted to the ICU were selected. We excluded ICU readmissions (37), ICU admissions who stayed less than 24 hours (44), and patients with unavailable medical charts (36).

Outcome measure: In-ICU and 6-month mortality.

Main results: Multivariate logistic regression analysis and Cox proportional hazards models demonstrated that the variables associated with in-ICU and 6-month mortality were sepsis as the cause of admission (odds ratio [OR] = 3.16 [95% confidence interval [CI] 1.65-6.06]); hazards ratio [HR] = 1.37 [95% CI 1.01-1.88]), an Acute Physiology and Chronic Health Evaluation II score >19 [OR = 2.81 (95% CI 1.57-5.04); HR = 2.18 (95% CI 1.62-2.94)], mechanical ventilation during the first 24 hours [OR = 3.92 (95% CI 2.20-6.96); HR = 2.25 (95% CI 1.65-3.07)], and year of ICU admission [OR = 0.90 (95% CI 0.81-0.99); HR = 0.92 [95% CI 0.87-0.97)]. CD4 T-cell count <50 cells/mm(3) was only associated with ICU mortality [OR = 2.10 (95% CI 1.17-3.76)]. The use of ART in the ICU was negatively predictive of 6-month mortality in the Cox model [HR = 0.50 (95% CI 0.35-0.71)], especially if this therapy was introduced during the first 4 days of admission to the ICU [HR = 0.58 (95% CI 0.41-0.83)]. Regarding HIV-infected patients admitted to ICU without using ART, those who have started this treatment during ICU stay presented a better prognosis when time and potential confounding factors were adjusted for [HR 0.55 (95% CI 0.31-0.98)].

Conclusions: The ICU outcome of HIV-infected patients seems to be dependent not only on acute illness severity, but also on the administration of antiretroviral treatment.

Figure 1

Flow diagram of human immunodeficiency virus (HIV)-infected patients enrolled in the study at the Infectious Diseases Intensive Care Unit of the Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo from 1996 to 2006. ICU, intensive care unit.

Figure 2

Kaplan-Meier survival curves for all intensive care unit (ICU) human immunodeficiency virus (HIV)-infected patients stratified according to the use of antiretroviral therapy. The survival of patients who began antiretroviral therapy (ART) during ICU stay (green) was significantly different from patients without ART during ICU stay (p = 0.004) (black). The survival of patients with previous and continuous use of ART at the ICU (red) was not different from HIV-infected patients without antiretroviral therapy during ICU stay (p = 0.39).

Figure 3

Hazard ratio and confidence intervals according to the time of initiation of antiretroviral therapy in 278 HIV-infected patients admitted to the intensive care unit (ICU). Hazard ratios are adjusted on the basis of age, Acute Physiology and Chronic Health Evaluation II, year of admission, presence or absence of sepsis, Pneumocystis jirovecii pneumonia, comorbidities, hepatitis C, lactate dehydrogenase, previous use of antiretroviral therapy, time of human immunodeficiency virus diagnosis, and mechanical ventilation during the first day of ICU admission. ART, antiretroviral therapy.